1. Field of the Invention
The present invention relates to a self-rechargeable hybrid battery and an electronic device including the same.
2. Discussion of Related Art
Solar energy has many advantages over existing energy sources. For example, solar energy is unlimited, and may be used anywhere. Solar energy is being advantageously used in a variety of fields. For example, a solar cell is mounted at a portion of a building or car onto which sunlight is radiated, and solar energy is converted to electricity by the mounted solar cell. Electricity obtained as described above may be applied to a diversity of electronic devices as lighting equipment such as lighting for buildings, a power source for cars, or portable electronic components such as mobile phones or video recorders. Although solar energy is obtained in the daytime when sunlight is radiated, when electricity obtained as described above is accumulated, electricity may be used at night or in rainy weather without sunlight. Accordingly, when the above described solar energy is used, solar energy may become an energy source not causing the depletion or destruction of natural resources.
Examples of electrical energy storage devices which store electricity converted by a solar cell include secondary batteries such as Ni-MH batteries, Ni—Cd batteries, lead-acid batteries and lithium secondary batteries, supercapacitors having high power density and unlimited charge/discharge life, aluminum electrolytic capacitors, ceramic capacitors, etc.
The capacitors use electrostatic characteristics, and thus have unlimited charge/discharge life and are semi-permanently available as compared to batteries using an electrochemical reaction. Further, the speed of charging/discharging energy of the capacitors is very fast, and thus the power density of the capacitors is dozens of times higher than that of the batteries. Accordingly, the capacitors have characteristics that the existing chemical cell batteries may not realize, and thus the application field of the capacitors is being increased throughout the industry. Particularly, in the era of high oil prices, the effectiveness of the capacitor as an energy buffer is being increased day by day in the development field of the next generation environmentally friendly vehicle such as an electric vehicle (EV), a hybrid electric vehicle (HEV), a fuel cell vehicle (FCV), etc.
That is, when a self-rechargeable hybrid battery including a solar cell which converts the solar energy to electricity and a capacitor which stores the electricity output from the solar cell for charging is manufactured, resources having high power density and charge/discharge life may be obtained without destroying the environment.
However, although electronic devices based on a transparent and flexible display are being developed currently, transparent batteries to drive the electronic devices have not yet been manufactured. Accordingly, there is a need to manufacture a transparent electrode of the batteries. To this end, the electrode is required to have low surface resistance, a high electrical conductivity, a high electrical capacity and preferably, a light transmittance of 80% or more in the visible light region.